This invention is directed generally to a novel disposable tint pack assembly for use in contact lens tinting, and more particularly, to an assembly including a plurality of disposable, flexible storage pouches for storing quantities of fluids utilized in the automated tinting of contact lenses, and dispensing structures coupled therewith for dispensing incremental quantities of fluid therefrom during the tinting process.
A novel automated contact lens tinting apparatus is disclosed and claimed in the co-pending application of Francis E. Ryder et al., Ser. No. 715,095 filed Mar. 22, 1985, now U.S. Pat. No. 4,632,055. The present application, as well as this co-pending application are directed to the tinting or coloration of contact lenses and more particularly to a novel apparatus and method for carrying out such tinting in an automated fashion.
In recent years, the so-called "soft" contact lenses have met with widespread acceptance. The soft lenses are generally manufactured from a hydrophylic plastic material. That is, this type of lense can absorb and retain water and thereby become soft and pliable, and are therefore relatively comfortable for extended periods of wear.
It has also become accepted to tint these soft contact lenses, and as such the tinted or colored lenses provide additional advantages or attractions to many wearers. For example, the tinted lenses may be desired by patients for cosmetic reasons, such as correction of discoloration or disfigurement of the eyes caused by illness or accident. Such tinted lenses may be used by patients with diplopia to give the eyes a more normal appearance. Similarly, tinted or colored lenses may provide albino and aniridic patients with improved general ocular and facial appearance. Of course, such tinted lenses may also be utlilized to reduce light transmission and enchance visual comfort in the presence of high light levels, and also to enhance the general overall appearance of the wearer by providing an option as to eye color.
The above-referenced co-pending application of Ryder et al. sets forth a particularly advantageous apparatus and method for permitting a relatively simple and highly automated process of coloring or tinting contact lenses. The apparatus is sufficiently simple and reliable in operation to permit its use on the premises of an individual eye care provider, thereby avoiding the need for lenses to be custom ordered from a manufacturing facility, wherein relatively complex, and sophisticated equipment is used for the tinting process. Moreover, operation of the conventional manufacturing facility-type of equipment requires relatively skilled, highly trained technicians or operators, whereas the apparatus of the above-mentioned co-pending application requires but a minimum of training and supervision to operate reliably.
Generally speaking, the tinting of lenses involves the placement of the lens on a fixture discussed more fully in the above-referenced co-pending application and other applications referenced therein. Thereafter, a predetermined amount of heat energy is applied to the lens to enhance its receptiveness to the subsequent setting or fixing of dye thereupon. The dyeing process is then performed on the heated lens in a number of operations which are carried out in a given sequence. These operations include initially applying the dye in the desired, generally annular pattern to the lens carried within the fixture. The dye is applied to an interior surface of the lens and allowed to permeate into the pores of the material during an ensuing period. Thereafter, several additional fluids are applied in sequence to complete the dying and tinting process, to accomplish the setting of the dye by rinsing the lens with these additional fluids.
More particularly, following initial application of the dye and an initial drying or setting period, a sodium nitrite solution of on the order of 5% concentration is applied. Immediately thereafter, a dilute sulphuric acid solution also of on the order of 5% concentration is applied. This latter solution acts as an oxidizing agent, so that the water soluble dye precipitates and becomes a water insoluble salt entrapped within the polymer matrix of the lens. Finally, a sodium bicarbonate solution of on the order of 5% concentration is applied to neutralize the sulphuric acid. While the above-referenced co-pending application of Ryder et al. discloses and claims a novel apparatus for carrying out the above dyeing process in an automated fashion, the present application provides a novel, disposable tint apparatus for containing premeasured quantities of the fluids utilized in the process. These fluids include a dyeing solution of desired color, as well as each of the above-described solutions in separate packages or pouches, to be applied in automated fashion by the apparatus of the co-pending application.
One problem that has arisen in connection with the automated dying of contact lenses is the relative instability and shaft shelf or operating life of the dying solution, once the fluid dye concentrate has been mixed with a suitable amount of water to form a solution of the desired concentration for application to the lens. In this regard, the introduction of oxygen both from the water mixed with the dye concentrate and from exposure to air during and after this mixing tends to break down the dye, such that it has a relatively short service life, once mixed or placed in solution with water.
Moreover, we have found it desirable to provide the premeasured quantities of solution, as well as dispensing mechanisms therefor in a disposable, sterile package. This assures that only enough dye and other solutions for tinting a predetermined, relatively small number of lenses (preferably on the order of 20) be provided in a disposable package. This disposability further enhances the maintenance of desired sterile and sanitary conditions of the apparatus and process. Also, the provision of but limited quaitities of dyeing solutions in disposable packages facilitates relatively simple and rapid changing of one disposable package for another when it is desired to tint but one or a few lenses in each of a variety of colors. That is, the disposable packages may be readily interchanged in the apparatus to permit an almost immediate resumption of tinting of further lenses in a new color. Additionally, it will be appreciated that the provision of but a limited quantity of the foregoing solutions facilitates the provision of but a limited quantity of the relatively unstable dye solution, thus limiting the period of time during which this solution will be in use and hence have an opportunity to deteriorate.
We have found that the provision of such disposable packages also requires that dispensing members or portions, which preferably comprise diaphragm pump-like members as shown generally in the above-mentioned co-pending application and as described more fully in this application, be attached to the packages and hence be disposable also. This in turn requires that these dispensing members be fabricated in a relatively inexpensive molding process from a moldable plastics material. However, it has been found that such plastics materials are generally oxygen permeable, and it will be recalled that the presence of oxygen tends to break down the dye, once in solution.
Accordingly, the present invention also extends to a novel compartmented pouch arrangement for containing the dye concentrate and a suitable quantity of water separately. Advantageously, the pouch arrangement of the invention permits ready and simple intermixing of the dye concentrate and water immediately prior to use thereof in the tinting operation. In this way, the shelf life of the dying solution is greatly extended, since the dye concentrate is mixed with the water portion only immediately prior to commencement of tinting, and the separate components are held in separate, air-tight sealed pouches prior to this time.
The present invention also includes a tray-like receptacle or carrier member which is advantageoue1y configured to cooperate with the tinting machine or apparatus described in the above-referenced co-pending application. In this regard, the tray or receptacle member both receives and arranges the pouches containing the dye and each of the other solutions described above in the proper order for automatic application of each by the apparatus in the order described above. As will be further described herein, novel releaseable retaining means are also provided for permitting relatively simple and expeditious preassembly of the individual dye and solution-containing pouch members, as well as the dispensing members coupled therewith, with the tray-like receptacle or carrier structure. Thereafter, none of the component pouches need be removed from the tray-like carrier either prior to or during the tinting operation, and the entire carrier and contents may be disposed of after tinting a predetermined number of lenses. However, the novel tray-like receptacle of the invention also permits ready access to the dye and water containing pouch-like portion to permit the above-described intermixing of the dye concentrate and water immediately prior to use thereof in the tinting process.